Toolholder

Abstract

A toolholder for use in shaping the blade of a screwdriver with a grinder having a grinding wheel and a guiding surface parallel to the axis of the wheel, the toolholder including a pair of blocks adapted to clamp the shank of the screwdriver between them, each block providing a guiding surface angularly related to the shank and disposed oppositely of the other block; clamps spaced along the axis to draw the block onto the shank and selectively adjustable to bring the guided surfaces into normal relation with a plane normal to the axis; and a pair of projections on the blocks bearing indicia indicating the relative spacing of their ends when the guided surfaces are in such normal relation, the toolholder being guided by engagement of one of the guided surfaces with the guiding surface to shape one side of the blade and being invertible with the screwdriver for guidance of the toolholder by engagement of the other of the guided surfaces by the guiding surface to shape the other side of the blade.

Having described my invention, what I claim as new and desire to secure by Letters Patent is: 
     
       1. A toolholder for use with a tool shaping device having a planar guiding surface and with a tool having a pair of opposite sides which are individually shaped by linear movement of the tool in a direction parallel to the surface, the holder comprising: A. a body having a pair of juxtaposed blocks adapted to receive the tool therebetween and individually bearing a pair of faces disposed oppositely of the body and individually corresponding to the sides of the tool, each face having a planar guided surface adapted to engage flatly the guiding surface of the shaping device for guidance of the body in sliding movement in said direction, and having a pair of portions disposed so as to be spaced in said direction when the guided surface of the blade is engaged with the guided surface for such guidance;   B. means for clamping the tool in the body centrally between the faces so that one side of the tool is shaped by the device when one of the guided surfaces engages the guiding surface and the other side of the tool is shaped by the device when the other of the guided surfaces engages the guiding surface, the clamping means including a pair of spaced, screwthreaded elements, each element individually connecting one portion of one block with the portion of the other block corresponding to said one portion along said direction when the guided surface of the blade is engaged with the guided surface for such guidance, so that rotation of the element in a predetermined direction urges the pair of portions associated therewith toward each other and so that selective rotation of the screwthreaded elements in said direction of rotation adjusts the guided surfaces precisely into normal relation to a plane of reference which is normal to said direction; and   C. means for indicating the relative spacing of the pair of portions of the blocks associated with one of the screw-threaded elements and means for indicating the relative spacing of the pair of portions of the blocks associated with the other of the screw-threaded elements, each indicating means indicating the relative spacing of the pair of portions associated with the screw-threaded element of said means when the guided surfaces are disposed precisely in said normal relation.   
     
     
       2. The toolholder of claim 1 wherein the shaping device has a planar surface parallel to said direction of linear movement and the tool has an end extending between the opposite sides thereof and wherein: A. said guided surfaces are convergent when in said normal relation; and   B. one of the blocks is provided with a planar surface substantially normal to a plane of reference bisecting the angle between the guided surfaces and adapted to engage flatly the planar surface of the shaping device for guidance of the toolholder in sliding movement in a direction along said surface of the shaping device, thereby guiding the holder for shaping of said end of the tool.   
     
     
       3. In combination, a device having a tool shaping element provided with a cylindrical periphery and adapted to rotate about the axis thereof and having a rest providing a planar guiding surface parallel to the axis; a tool having a shank extended along a longitudinal axis and having a pair of opposite sides to be shaped by engagement with the periphery in substantially identical, cylindrically concave configurations conforming to the periphery and disposed symmetrically and oppositely of the longitudinal axis; and a toolholder comprising: A. a pair of juxtaposed blocks, each block having a first face disposed toward the other block so as to engage the tool between said face and the first face of the other block with the tool extended from between the first faces with one of the sides of the tool disposed toward the axis and having a second face disposed oppositely of the other of the blocks providing a planar guided surface adapted flatly to engage the guiding surface of the rest and guide the block in sliding movement parallel to the axis to engage said one side with the edge;   B. means for maintaining the blocks in said juxtaposed relation in a direction along the axis; and   C. means for drawing the blocks toward each other into clamping relation with the tool so that, when said one side is shaped in such a concave configuration by engagement with the periphery, the blocks and the tool are invertible together in relation to the rest and the side of the tool opposite said one side subsequently shaped in such a concave configuration with the guided surface of said other block engaged in guiding relation with the guiding surface   D. each said block having a pair of opposite ends which are spaced in a direction along the axis when said guided surfaces are engaged with the guiding surface, the opposite ends of one block being disposed in individually adjacent relation to the corresponding ends of the other block;   E. the means for drawing the blocks toward each other comprises a pair of clamps individually related to the adjacent pairs of the ends for adjustably positioning the ends of each pair toward and from each other; and   F. the toolholder further comprises a pair of measuring elements individually related to the adjacent pairs of the ends and indicating the relative positions of the adjacent pairs of ends toward and from each other so as to indicate that the guided surfaces are substantially normal to a common plane of reference which is normal to the axis when one of said guided surfaces is flatly engaged with the guiding surface, whereby the cylindrically concave sides of the tool are shaped so that their respective axes are substantially parallel.   
     
     
       4. The toolholder for use in shaping a screwdriver or the like with a grinder, the screwdriver includes a shank elongated along a longitudinal axis and a blade mounted on one end of the shank and having opposite sides disposed oppositely of the axis and the grinder including a grinding wheel mounted for rotation about a rotational axis substantially conicident with the axis of the wheel and a rest providing a stationary, planar guiding surface parallel to the rotational axis, wherein the toolholder comprises: A. a pair of elongated blocks disposed in facing, juxtaposed relation and adapted to receive the shank therebetween and longitudinally centrally thereof in a predetermined disposition in which the longitudinal axis extends transversely of the blocks with the blade spaced transversely from the blocks, each block including (1) a pair of longitudinally opposite ends,   (2) a transverse side disposed toward the blade when the shank is received in said predetermined disposition,   (3) a first face disposed toward the other of the blocks,   (4) a second face disposed oppositely of the other of the blocks bearing an elongated planar guided surface extended longitudinally of the block between the ends thereof and adapted flatly to engage the guiding surface of the rest to guide the blocks in sliding movement parallel to the rotational axis, said guided surface and the guided surface of the other block converging in a direction away from the transverse side and being disposed so as substantially to intersect at the longitudinal axis when the guided surfaces are in normal relation to a reference plane including the longitudinal axis, and   (5) a notch disposed at one of the ends and extended through the block in a direction between the faces thereof;     B. means extended from one of the blocks and slidably engaged with the other block for restraining the blocks against relative longitudinal movement;   C. a pair of thumbscrews spaced longitudinally of the blocks and extended therethrough oppositely of the shank when the shank is received in said predetermined disposition, each thumbscrew having a head disposed oppositely of one of the blocks from the other of the blocks and having a shank screw-threadably connected to said other of the blocks so that tightening of the thumbscrew draws together the portions of each block through which the thumbscrew extends and brings the blocks into clamping engagement with the shank of the screwdriver;   D. a first projection fixedly mounted on one end of one of the blocks and extended from said one end toward the other of the blocks, the projection bearing indicia indicating the distance at said one end of said one block from the first face thereof to the first face of the other of the blocks; and   E. a second projection fixedly mounted on an end of one of the blocks opposite the end mounting the first projection, the second projection extending toward the adjacent end of the other of the blocks and bearing indicia indicating the distance at the end mounting the second projection from the first face of the block mounting the second projection to the first face of the other of the blocks, whereby the distance between the first faces at the longitudinally adjacent ends of the blocks can be equalized by selective tightening of the thumbscrews to bring the guided surfaces into said normal relation.   
     
     
       5. The toolholder of claim 4 wherein the ends of the blocks adjacent to the ends thereof mounting the first projection and the second projection have individual notches extended between the corresponding first face and the corresponding second face to receive the longitudinally corresponding one of the projections as the blocks are brought into said clamping engagement. 
     
     
       6. The toolholder of claim 4 wherein the rest has a planar surface parallel to the rotational axis and extended from the guiding surface in right-angular relation thereto oppositely therefrom the wheel, and wherein: A. the guided surface of each block is one of the surfaces of a V-shaped channel extended longitudinally of the block oppositely of the thumbscrews from the transverse side of the block; and   B. the other surfaces of said channel is planar and is disposed for slidable engagement with the surface extended from the guiding surface when the corresponding guided surface is flatly engaged with the guiding surface to maintain the toolholder at a predetermined spacing from the wheel.   
     
     
       7. The toolholder of claim 6 wherein the blade has a tip surface interconnecting the opposite sides thereof, and wherein each block has a longitudinally extending step spaced toward the transverse side of the block from the thumbscrews, the step providing a first surface which is substantially parallel to the rotational axis when the screwdriver is received in said predetermined disposition and providing a second surface which is substantially normal to the longitudinal axis when the screwdriver is so received, said first surface and said second surface being adapted, respectfully, to engage the guiding surface of the rest and the surface thereof extended from the guiding surface thereby to guide the holder in sliding motion parallel to the rotational axis with the tip surface engaged with the wheel.